Of course the title is all tongue-in-cheek, but there are so many photos from so many sources that show so much weird stuff. I hate to say the obvious, but we will just have to watch the skies and see what is true and what isn't for ourselves. And it won't be long now...
This was the first video release by BPEarthwatch...
This was the first video release by BPEarthwatch...
What he's talking about in these videos is what appears to be a bright (and therefore hot and powerful jet visible on the front of the comet, not in the tail, but the nose) jet preceding the comet on it's path.
More on these images which were taken from the Hubble Telescope in May of this year. So what is it?
The below article and images are from Bruce Gary's ground-based telescope and his predictions for the Comet based on his observations. Interesting stuff.
Comet ISON Observations by an Amateur ObserverWebmaster: Bruce Gary, Last updated: 2013.10.01, 20.7 UT
This website is a record of observations of Comet C/2012 S1 (ISON) by amateur Bruce Gary, using a Celestron 11-inch telescope at the Hereford Arizona Observatory (G95). When I was the first to obtain a "recovery image" of the comet on August 12, after it had been unobservable during June/July, and when I noted that it was fainter than expected, an unexpected amount of publicity for this web page occurred. I therefore feel obligated to maintain this web site with observations and analyses worthy of that attention. My long-term goal used to be a monitoring of the coma by measuring brightness versus diameter at 3 wavelengths (g'r'i') with a goal of detecting brightness outbursts caused by temperature-dependent volatile activity. Measurements on several dates (after reappearing from behind the sun) show that the comet is brightening at a lower rate than expected, as if the activity level on the nucleus surface (i.e., Af-rho) is not changing as it approaches the sun. By now ISON has probably passed the "frost line," so why is it unresponsive to the increasing level of solar illumination (and surface temperature)? There may be a wonderfully simple explanation for this, and it predicts a late "coming alive" for this particular comet. The recent "discovery" of a jet feature may be the key in understanding Comet ISON's behavior during the past 7 weeks.
Recent Updates:
Oct 02, 00.3 UT: Added r'-mag vs. photometry aperture (possibly showing another outer coma erosion event). Updated R-mag vs date plot.
Oct 01, 20.7 UT: Added image from Gary on Oct 01.
Oct 01, 06.8 UT: Added a section (near bottom) on "Primer on Asteroid/Comet Surface Temperatures."
Sep 30, 22.0 UT: Added several images, by several observers on several dates, enhanced by Toni Scarmato, showing a persistent jet pointing toward the sun. This jet was also seen in HST images, enhanced by Scarmato, that were taken in April and May.
Sep 30, 03.3 UT: Replaced stacked image for Sep 29 showing more detail & more of tail (5.0 'arc long).
Sep 29, 22.7 UT: Updated plot of mag vs. date to include model for a comet with typical "activity vs. proximity to sun," which shows stark contrast with ISON's behavior.
Sep 29, 19.1 UT: Added Sep 29 image, plot of mag vs. coma photometry aperture and updated mag vs. date model fit. Brightness & coma size recovered Sep 24 fade and shrinkage (due to solar wind erosion of coma?).
My model fit to R-mag measurements by Dennis Whitmer and Bruce Gary (that I have processed for a photometric R-mag measurement). My r'-mag's have been adjusted by -0.20 mag to be equivalent to Rc-mag's. Pre-August data is ignored in deriving this fit. Equation term "delta" is distance of comet from Earth [a.u.] and "r" distance of comet from sun. The "log(r) coefficient" for a typical comet is ~ 12 (usually between 9 and 18). ISON's current "log(r) coefficient" of about zero is unusually small, correesponding to NO change of activity (constant Af-rho); but this might be typical for "pristine" comets making their first entry into the solar system from the Oort cloud. (When the comet is closer to the sun than 20 degrees a dotted trace is used.) Notice the Sep 24 fade to Rc = 13.5 (by observers Whitmer and Gary), followed by a recovery within ~ 5 days (on Sept 29). This might be due to a stronger than usual solar wind on ~ Sep 24 eroding the coma (and feeding the tail), followed by normal solar wind and coma recovery (this theory is consistent with evidence that the coma had shrunk on Sep 24, mostly in outer regions, as described below). A similar erosion of the outer coma might have occurred on Oct 01.
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Sunward Jet Analysis
Toni Scarmato has enhanced images for which he was a participating observer and found a jet pointed toward the sun, similar to what was seen in HST images taken in April and May, 2013. Toni has also enhanced images that I have taken on a couple dates. All of them show the same jet. Here are his enhanced images (most recent at top):
Scarmato enhancement (using flase colors) of Gary stacked image, Sep 29, Cb filter, 11-inch telescope, showing jet on sunward side of comet.
Left: Enhancement of stacked image by Gary, Sep 29, Cb-band. Right: Brightness profile along sun/comet line.
Scarmato enhancement (using false colors) of Sep 25 stacked image by A. Brosio and T. Scarmato, with a 10-inch telescope, showing a jet on the sunward side (slightly offset from the comet/sun line).
Scarmato enhancement (using false colors) of Sep 24 stacked image by A. Brosio and T. Scarmato, made with a 10-inch telescope, showing a jet on the sunward side.
For comparison, here are two HST images that have also been enhanced by Scarmato. The original (unenhanced) images were taken by They both show a bright region, jet-shaped, extending to the lower-left. These enhanced images are copyrighted.
Scarmato enhancement of Hubble Space Telescope images taken by Prof. J. Yang-Li (PI). This image is copyrighted by Scarmato.
Scarmato enhancement of Hubble Space Telescope images taken by Z. Levay (PI). This image is copyrighted by Scarmato.Interpretation of the jet features is underway, with a publication in preparation.
